Display device

ABSTRACT

A display device includes a display module including a display panel and a support member including a first surface facing a rear surface of the display panel and a second surface opposite to the first surface, and a guide unit disposed on the second surface of the support member. The display module includes first and second folding portions, a central portion disposed between the first and second folding portions and left and second display portions. The guide unit includes a rotation part overlapping the central portion, a first connection part connected to the rotation part, a second connection part connected to the rotation part, a wire part fixed to the first display portion and fixed to the second connection part, and an elastic part fixed to the second surface of the support member and fixed to the rotation part, the first connection part or the second connection part.

This application claims priority to Korean Patent Application No.10-2019-0052892, filed on May 7, 2019, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND

The disclosure relates to a display device, and more particularly, to adisplay device with improved reliability.

Display devices for displaying images may be included in electronicdevices for providing images to users, such as smart phones, digitalcameras, notebook computers, navigation systems, and smart televisions.Display devices may generate images and may provide the generated imagesto users through display screens.

Display devices having various shapes have been developed with thedevelopment of techniques. For example, foldable display devices capableof being curved, folded and/or rolled have been developed. The foldabledisplay devices of which shapes can be variously changed may be easilyportable and may improve convenience of users.

SUMMARY

The disclosure may provide a display device capable of reducing ormitigating the interference of folding portions of a display module.

In an embodiment of the invention, a display device includes a displaymodule including a display panel including a front surface and a rearsurface opposite to the front surface and a support member including afirst surface facing the rear surface of the display panel and a secondsurface opposite to the first surface, and a guide unit disposed on thesecond surface of the support member. In such an embodiment, the displaymodule includes a first folding portion foldable with a radius ofcurvature, a second folding portion spaced apart from the first foldingportion and foldable with a radius of curvature which is equal to orgreater than the radius of curvature of the first folding portion, acentral portion disposed between the first and second folding portions,a first display portion spaced apart from the central portion with thefirst folding portion interposed therebetween, and a second displayportion spaced apart from the central portion with the second foldingportion interposed therebetween. The guide unit includes a rotation partoverlapping the central portion, a first connection part connected tothe rotation part, a second connection part spaced apart from the firstconnection part and connected to the rotation part, a wire partincluding a first end fixed to the first display portion and a secondend fixed to the second connection part, and an elastic part including afirst end fixed to the second surface of the support member and a secondend fixed to at least one part selected from the rotation part, thefirst connection part and the second connection part.

In an embodiment, the first folding portion may be foldable about afirst imaginary folding axis extending in a predetermined direction. Insuch an embodiment, the first connection part may overlap the secondfolding portion in a first state in which the first folding portion isunfolded, and the first connection part may be spaced apart from thesecond folding portion in a second state in which the first foldingportion is folded about the first imaginary folding axis.

In an embodiment, the second folding portion may be foldable about asecond imaginary folding axis extending in the predetermined direction.In the second state, the display module may be in-folded in a way suchthat the second surface of the support member overlapping the firstdisplay portion overlaps the front surface of the display paneloverlapping the second display portion.

In an embodiment, the second folding portion may be foldable about asecond imaginary folding axis extending in the predetermined direction.In such an embodiment, in the second state, the display module may beout-folded in a way such that the second surface of the support memberoverlapping the central portion overlaps the second surface of thesupport member overlapping the second display portion.

In an embodiment, the first end of the elastic part may be fixed to thesecond surface of the support member overlapping the second displayportion, and the second end of the elastic part may be fixed to thefirst connection part.

In an embodiment, the first end of the elastic part may be fixed to thesecond surface of the support member overlapping the central portion,and the second end of the elastic part may be fixed to the rotationpart.

In an embodiment, the first end of the elastic part may be fixed to thesecond surface of the support member overlapping the first displayportion, and the second end of the elastic part may be fixed to thesecond connection part.

In an embodiment, the display device may further include a firstsub-connection part connecting the first connection part and therotation part, and a second sub-connection part connecting the secondconnection part and the rotation part.

In an embodiment, the display device may further include wall partswhich guide movement directions of the first and second connectionparts.

In an embodiment, the elastic part may include a compression spring or atension spring.

In an embodiment, the elastic part may be disposed between the rotationpart and the second surface of the support member overlapping thecentral portion, and the elastic part may include a torsion springhaving a constant torque.

In an embodiment, each of the first and second folding portions mayinclude a hinge.

In an embodiment of the invention, a display device includes a displaymodule including a first folding portion foldable with a radius ofcurvature about a first imaginary folding axis extending in apredetermined direction, a second folding portion foldable with a radiusof curvature, which is equal to or greater than the radius of curvatureof the first folding portion, about a second imaginary folding axisextending in the predetermined direction, a central portion disposedbetween the first and second folding portions, a first display portionspaced apart from the central portion with the first folding portioninterposed therebetween, and a second display portion spaced apart fromthe central portion with the second folding portion interposedtherebetween; and a guide unit disposed under the display module, wherethe guide unit includes a rotation part overlapping the central portion,a first connection part connected to the rotation part, and a secondconnection part spaced apart from the first connection part andconnected to the rotation part. In such an embodiment, the firstconnection part overlaps the second folding portion in a first state inwhich the first folding portion is unfolded, and the first connectionpart is spaced apart from the second folding portion in a second statein which the first folding portion is folded about the first imaginaryfolding axis.

In an embodiment, the display module may include a display panelincluding a front surface and a rear surface opposite to the frontsurface, and a support member including a first surface facing the rearsurface of the display panel and a second surface opposite to the firstsurface.

In an embodiment, the second folding portion may be folded about thesecond imaginary folding axis extending in the predetermined direction.In the second state, the display module may be in-folded in such a waythat the second surface of the support member overlapping the firstdisplay portion overlaps the front surface of the display paneloverlapping the second display portion.

In an embodiment, the second folding portion may be folded about thesecond imaginary folding axis extending in the predetermined direction.In the second state, the display module may be out-folded in such a waythat the second surface of the support member overlapping the centralportion overlaps the second surface of the support member overlappingthe second display portion.

In an embodiment, the guide unit may further include a wire partincluding a first end fixed to the first display portion and a secondend fixed to the second connection part, and an elastic part including afirst end fixed to the second surface of the support member and a secondend fixed to at least one of the rotation part, the first connectionpart, or the second connection part.

In an embodiment, the first end of the elastic part may be fixed to thesecond surface of the support member overlapping the second displayportion, and the second end of the elastic part may be fixed to thefirst connection part.

In an embodiment, the first end of the elastic part may be fixed to thesecond surface of the support member overlapping the central portion,and the second end of the elastic part may be fixed to the rotationpart.

In an embodiment, the first end of the elastic part may be fixed to thesecond surface of the support member overlapping the first displayportion, and the second end of the elastic part may be fixed to thesecond connection part.

In an embodiment, the display device may further include a firstsub-connection part connected to the first connection part and therotation part, and a second sub-connection part connected to the secondconnection part and the rotation part.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate exemplaryembodiments of the invention and, together with the description, serveto explain principles of the invention. In the drawings:

FIG. 1 is a perspective view illustrating a display device according toan embodiment of the invention;

FIG. 2 is an exploded perspective view illustrating the display deviceof FIG. 1;

FIG. 3A is a perspective view illustrating a display module of which anarea is folded, according to an embodiment of the invention;

FIG. 3B is a perspective view illustrating a display module of whichareas are folded, according to an embodiment of the invention;

FIG. 3C is a perspective view illustrating a display module of whichareas are folded, according to an embodiment of the invention;

FIG. 4A is a cross-sectional view illustrating a display panel accordingto an embodiment of the invention;

FIG. 4B is an equivalent circuit diagram of a pixel according to anembodiment of the invention;

FIG. 5A is a plan view illustrating a display module according to anembodiment of the invention;

FIG. 5B is a plan view illustrating a state in which the display moduleof FIG. 5A is folded;

FIG. 6A is a plan view illustrating a display module according to analternative embodiment of the invention;

FIG. 6B is a plan view illustrating a state in which the display moduleof FIG. 6A is folded;

FIG. 7A is a plan view illustrating a display module according toanother alternative embodiment of the invention;

FIG. 7B is a plan view illustrating a state in which the display moduleof FIG. 7A is folded;

FIG. 8A is a plan view illustrating a display module according toanother alternative embodiment of the invention;

FIG. 8B is a plan view illustrating a state in which the display moduleof FIG. 8A is folded;

FIG. 9A is a plan view illustrating a display module according toanother alternative embodiment of the invention;

FIG. 9B is a plan view illustrating a state in which the display moduleof FIG. 9A is folded; and

FIG. 10 is a plan view illustrating a display module according toanother alternative embodiment of the invention.

DETAILED DESCRIPTION

The invention now will be described more fully hereinafter withreference to the accompanying drawings, in which various embodiments areshown. The invention may, however, be embodied in many different forms,and should not be construed as limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill be thorough and complete, and will fully convey the scopes of theinvention to those skilled in the art. Like reference numerals refer tolike elements throughout.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may be present. Incontrast, the term “directly” means that there are no interveningelements. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “Or” means “and/or.” As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. It will be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one element, component, region, layer or section fromanother region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings herein.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system).

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference tocross-sectional illustrations and/or plane illustrations that areidealized exemplary illustrations. In the drawings, the thicknesses oflayers and regions are exaggerated for clarity. Accordingly, variationsfrom the shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, are to be expected. Thus,exemplary embodiments should not be construed as limited to the shapesof regions illustrated herein but are to include deviations in shapesthat result, for example, from manufacturing. For example, an etchingregion illustrated as a rectangle will, typically, have rounded orcurved features. Thus, the regions illustrated in the figures areschematic in nature and their shapes are not intended to illustrate theactual shape of a region of a device and are not intended to limit thescope of exemplary embodiments.

Hereinafter, exemplary embodiments of the invention will be described indetail with reference to the accompanying drawings.

FIG. 1 is a perspective view illustrating a display device according toan embodiment of the invention. FIG. 2 is an exploded perspective viewillustrating the display device of FIG. 1. FIG. 3A is a perspective viewillustrating a display module of which an area is folded, according toan embodiment of the invention. FIG. 3B is a perspective viewillustrating a display module of which areas are folded, according to anembodiment of the invention. FIG. 3C is a perspective view illustratinga display module of which areas are folded, according to an embodimentof the invention. FIG. 4A is a cross-sectional view illustrating adisplay panel according to an embodiment of the invention. FIG. 4B is anequivalent circuit diagram of a pixel according to an embodiment of theinvention. Hereinafter, a display device according to an embodiment ofthe invention will be described with reference to FIGS. 1 to 4B.

Referring to FIGS. 1 to 3C, an embodiment of a display device EDaccording to the invention may display an image IM through a displaysurface IS defined thereon. The display surface IS may be parallel to aplane defined by a first direction DR1 and a second direction DR2. Anormal direction of the display surface IS (e.g., a thickness directionof the display device ED) may be indicated by a third direction DR3.FIG. 1 illustrates the display device ED in a first state in which thedisplay device ED (e.g., a foldable display device) is unfolded.

An embodiment of the foldable display device ED applied to a mobilephone is illustrated in FIG. 1. Even though not shown in the drawings,electronic modules, a camera module and a power module, which aremounted on a main board, may be disposed together with the foldabledisplay device ED in a bracket and/or a case to constitute the mobilephone. However, embodiments of the invention are not limited thereto.Alternatively, the foldable display device ED may also be applied tolarge-sized electronic devices (e.g., televisions and monitors) or smalland middle-sized electronic devices (e.g., tablets, car navigationunits, game consoles, and smart watches). As described above, thefoldable display device is illustrated as an embodiment of the displaydevice ED in FIGS. 1 and 2.

The display device ED may display the image IM on the display surface ISparallel to the first and second directions DR1 and DR2 in the thirddirection DR3. The display surface IS, on which the image IM isdisplayed, may correspond to a front surface of the display device ED.The image IM may include a dynamic image and a static image. In FIG. 1,an internet search box is illustrated as an example of the image IM.

The display device ED may include a window member WM, a display moduleDM, and an outer case EDC. The components of the display device ED areschematically illustrated in FIG. 2.

The window member WM may be disposed on the display module DM. Thewindow member WM may be coupled to the outer case EDC such that thewindow member WM and the outer case EDC collectively define the exteriorof the display device ED. The window member WM may be coupled to theouter case EDC to enclose the display module DM not to be exposed to anoutside, thereby effectively protecting the display module DM.

The window member WM may include a transmission area TA and a bezel areaBZA. The display surface IS of the display device ED may besubstantially defined by the transmission area TA and the bezel area BZAof the window member WM.

The transmission area TA may be an area in which the image IM isdisplayed. A user may view the image IM through the transmission areaTA. A shape of the transmission area TA may be variously modified.

The bezel area BZA may be adjacent to the transmission area TA. Thebezel area BZA may have a predetermined color. The bezel area BZA maysurround the transmission area TA when viewed in a plan view. Thus, theshape of the transmission area TA may be substantially defined by thebezel area BZA. However, embodiments of the invention are not limitedthereto. In an alternative embodiment, the bezel area BZA may beadjacent to only a single side of the transmission area TA or may beomitted, for example. In embodiments of the invention, the displaydevice ED may be variously embodied and is not limited to a specificembodiment.

The display module DM may include a display panel DP and a supportmember SM. The display panel DP may include a front surface DP-U and arear surface DP-B opposite to the front surface DP-U. An active area AAand a peripheral area NAA may be defined in the front surface DP-U. Thedisplay panel DP may activate the active area AA by an electricalsignal. The display panel DP may display the image IM in the activatedactive area AA. The transmission area TA may overlap at least an entireportion of the active area AA. The rear surface DP-B may be defined as asurface that is in contact with the support member SM.

The peripheral area NAA may be adjacent to the active area AA. Theperipheral area NAA may surround an edge of the active area AA whenviewed in a plan view. In an embodiment, the peripheral area NAA maysurround all of edges of the active area AA. However, embodiments of theinvention are not limited thereto. In an alternative embodiment, theperipheral area NAA may be adjacent to only a single edge of the activearea AA.

Various kinds of signal lines and/or electronic elements for providingelectrical signals to the active area AA may be disposed in theperipheral area NAA. The peripheral area NAA may be covered by the bezelarea BZA and thus may not be visible from an outside.

Referring to FIG. 4A, an embodiment of the display panel DP may includea display unit DS and an input sensing layer TP. The input sensing layerTP may be disposed on the display unit DS.

The display unit DS may include a base layer BSL, a pixel layer PXLdisposed on the base layer BSL, and a protective layer PTL covering thepixel layer PXL. The base layer BSL, the pixel layer PXL and theprotective layer PTL may be sequentially stacked one on another in thethird direction DR3. The base layer BSL may define the rear surface DP-Bof the display panel DP and may have flexibility. The pixel layer PXLmay include a plurality of pixels (not shown) and may be driven byapplied electrical signals to generate the image IM. The protectivelayer PTL may protect the pixel layer PXL and may have a structure inwhich an organic layer and an inorganic layer are stacked, e.g.,alternately and repeated stacked one on another. The input sensing layerTP may be disposed on the protective layer PTL.

FIG. 4B illustrates an equivalent circuit diagram of one pixel PX of thepixels included in the pixel layer PXL. An embodiment of the pixel PXmay include an organic light emitting element used in an organic lightemitting display panel.

The pixel PX may be connected to a scan line Si, a data line Dj, and anemission line Ei. Here, ‘i’ and ‘j’ are natural numbers. The pixel PXmay include a light emitting element OLED, a driving transistor T1, acapacitive element Cst, a switching transistor T2, and an emissioncontrol transistor T3. The light emitting element OLED may be an organiclight emitting element.

A source terminal of the driving transistor T1 may be provided with afirst voltage ELVDD, and a drain terminal of the driving transistor T1may be connected to a source terminal of the emission control transistorT3. A gate terminal of the driving transistor T1 may be connected to adrain terminal of the switching transistor T2.

A gate terminal of the switching transistor T2 may be connected to thescan line Si, and a source terminal of the switching transistor T2 maybe connected to the data line Dj. A first electrode of the capacitiveelement Cst may be connected to the source terminal of the drivingtransistor T1, and a second electrode of the capacitive element Cst maybe connected to the gate terminal of the driving transistor T1.

A gate terminal of the emission control transistor T3 may be connectedto the emission line Ei, and a drain terminal of the emission controltransistor T3 may be connected to an anode of the light emitting elementOLED. A cathode of the light emitting element OLED may receive a secondvoltage ELVSS. A level of the second voltage ELVSS may be lower than alevel of the first voltage ELVDD.

The switching transistor T2 may be turned on in response to a scansignal SS provided thereto through the scan line Si. The turned-onswitching transistor T2 may provide a data voltage VD received throughthe data line Dj to the gate terminal of the driving transistor T1. Thecapacitive element Cst may store the data voltage VD applied to the gateterminal of the driving transistor T1 and may retain the stored datavoltage VD after the switching transistor T2 is turned off.

The gate terminal of the emission control transistor T3 may receive anemission signal EM through the emission line Ei, and thus the emissioncontrol transistor T3 may be turned on. The turned-on emission controltransistor T3 may provide a current bled flowing through the drivingtransistor T1 to the light emitting element OLED. The pixel PX may emitlight while the emission signal EM is applied, and an intensity of thelight emitted from the light emitting element OLED may be determined orchanged based on the amount of the current bled provided to the lightemitting element OLED.

In one embodiment, for example, the transistors T1 to T3 of the pixel PXmay be P-type metal-oxide-semiconductor (“PMOS”) transistors. However,embodiments of the invention are not limited thereto. In an alternativeembodiment, the transistors T1 to T3 of the pixel PX may be N-typemetal-oxide-semiconductor (“NMOS”) transistors.

The input sensing layer TP may be a layer for sensing an external input.The input sensing layer TP may include an conductive layer and aninsulating layer for insulating the conductive layer.

The external input may include at least one of various kinds of inputsprovided from the outside of the display device ED. The external inputmay be provided in various forms. The external input may include aninput (e.g., a hovering input) proximate to the display device ED by apredetermined distance as well as a touch of a part (e.g., a finger) ofa user's body, for example. In addition, the external input may beprovided in other various forms such as force, pressure, and/or light.

Referring back to FIGS. 1 and 2, the support member SM may include afirst surface SM-U and a second surface SM-B. The first surface SM-U maybe in contact with the rear surface DP-B of the display panel DP. Thesecond surface SM-B may be opposite to the first surface SM-U. Thesecond surface SM-B may be in contact with the outer case EDC. In anembodiment, as shown in FIGS. 3A to 3C, the support member SM mayinclude hinge portions HG1 and HG2. An area in which a first hingeportion HG1 is disposed may be defined as a first folding portion FD1 ofthe display module DM. An area in which a second hinge portion HG2 isdisposed may be defined as a second folding portion FD2 of the displaymodule DM. In an embodiment, the hinge portions HG1 and HG2 may behinges. In such an embodiment, the hinge may be foldable with apredetermined radius of curvature, but embodiments of the invention arenot limited to a specific hinge.

Although not shown in the drawings, an embodiment of the support memberSM may further include a functional layer for improving reliability ofthe display panel DP. The functional layer may be disposed under thedisplay panel DP. The functional layer may include a plurality oflayers. In one embodiment, for example, the functional layer may includea cushion layer having a foam shape and configured to absorb an impactof the display panel DP, a light blocking layer configured to blocklight provided from the display panel DP, and a heat dissipation layerconfigured to discharge heat generated from the display panel DP to theoutside.

An embodiment of the display module DM may include a plurality of areasarranged in the first direction DR1. In one embodiment, for example, thedisplay module DM may include (or be divided into) a central portion CA,a first display portion DA1, a second display portion DA2, the firstfolding portion FD1, and the second folding portion FD2.

The first folding portion FD1 may be defined as an area overlapping thefirst hinge portion HG1. Herein, the phrase “one element overlapsanother element” may mean the one element overlaps the another elementwhen viewed from a plan view in a thickness direction of the displaydevice ED. The first folding portion FD1 may be foldable with apredetermined radius of curvature about a first folding axis FX1extending in the second direction DR2.

Referring to FIG. 3A, when the first folding portion FD1 is folded aboutthe first folding axis FX1, the display module DM may be in-folded in away such that the front surface DP-U of the display panel DP overlappingthe first display portion DA1 overlaps or faces the front surface DP-Uof the display panel DP overlapping the central portion CA.

According to an embodiment of the invention, a state in which the firstfolding portion FD1 of the display module DM is unfolded may be definedas the first state, as illustrated in FIG. 2. A state in which the firstfolding portion FD1 is folded about the first folding axis FX1 may bedefined as a second state, as illustrated in FIG. 3A.

The second folding portion FD2 may be defined as an area overlapping thesecond hinge portion HG2. The second folding portion FD2 may be foldablewith a predetermined radius of curvature about a second folding axisFX2-A or FX2-B extending in the second direction DR2. The radius ofcurvature of the second folding portion FD2 when the second foldingportion FD2 is folded about the second folding axis FX2-A or FX2-B maybe equal to or greater than the radius of curvature of the first foldingportion when the first folding portion FD1 is folded about the firstfolding axis FX1.

Referring to FIG. 3B, in the second state in which the first foldingportion FD1 is folded about the first folding axis FX1 and the secondfolding portion FD2 is folded about the second folding axis FX2-A, thedisplay module DM may be in-folded in a way such that the second surfaceSM-B of the support member SM overlapping the first display portion DA1overlaps with or faces the front surface DP-U of the display panel DPoverlapping the second display portion DA2. In such a state, the radiusof curvature of the second folding portion FD2 may be greater than theradius of curvature of the first folding portion FD1.

Referring to FIG. 3C, in the second state in which the first foldingportion FD1 is folded about the first folding axis FX1 and the secondfolding portion FD2 is folded about the second folding axis FX2-B, thedisplay module DM may be out-folded in such a way that the secondsurface SM-B of the support member SM overlapping the central portion CAoverlaps or faces the second surface SM-B of the support member SMoverlapping the second display portion DA2. In such a state, the radiusof curvature of the second folding portion FD2 may be equal to orgreater than the radius of curvature of the first folding portion FD1.

In FIGS. 3A to 3C, the window member WM and the outer case EDC areomitted for the purpose of ease and convenience in description andillustration. However, the window member WM and the outer case EDC maybe coupled to each other and may be folded in a substantially same shapeas the display module DM illustrated in FIGS. 3A to 3C.

In an embodiment of the invention, the display device ED includes aplurality of the folding portions FD1 and FD2, such that the shape ofthe display device ED may be variously changed according to the intendeduse. Thus, convenience of use of the display device ED may be increasedor improved.

FIG. 5A is a plan view illustrating a display module according to anembodiment of the invention. FIG. 5B is a plan view illustrating a statein which the display module of FIG. 5A is folded. Hereinafter, the sameor like components in FIGS. 5A and 5B as those described above withreference to FIGS. 1 to 4B will be indicated by the same referencecharacters, and any repetitive detailed description thereof will beomitted.

In an embodiment, the display device ED may include a guide unit LM. Theguide unit LM may be disposed on the second surface SM-B of the supportmember SM. In such an embodiment, the guide unit may determine a foldedorder of the plurality of folding portions FD1 and FD2. Hereinafter, theguide unit LM will be described in detail.

In an embodiment, the guide unit LM may include a rotation part LP, afirst connection part LK1, a second connection part LK2, a wire part WR,and an elastic part SP-A or SP-B.

FIG. 5A illustrates arrangement of the components included in the guideunit LM in the first state of the display module DM (i.e., the unfoldedstate of the display module DM, see FIG. 1 or 2).

In an embodiment, a first opening OP1 and a second opening OP2 aredefined in the rotation part LP. The rotation part LP may be disposed onthe second surface SM-B of the support member SM overlapping the centralportion CA. The rotation part LP may be coupled to the second surfaceSM-B of the support member SM through a rotation shaft CL. The rotationpart LP may be rotatable about the rotation shaft CL at a predeterminedangle.

The first connection part LK1 may include a first protrusion SC1. Thefirst connection part LK1 may extend in the first direction DR1. Thefirst connection part LK1 may be connected to the rotation part LP. Thefirst protrusion SC1 may be disposed in the first opening OP1 of therotation part LP. An area of the first opening OP1 may be greater thanan area of the first protrusion SC1. Thus, the first opening OP1 mayhave a space in which the first protrusion SC1 is movable.

The second connection part LK2 may include a second protrusion SC2. Thesecond connection part LK2 may extend in the first direction DR1. Thesecond connection part LK2 may be connected to the rotation part LP. Thesecond protrusion SC2 may be disposed in the second opening OP2 of therotation part LP. An area of the second opening OP2 may be greater thanan area of the second protrusion SC2. Thus, the second opening OP2 mayhave a space in which the second protrusion SC2 is movable.

According to an embodiment of the invention, the first and secondconnection parts LK1 and LK2 may be connected to the rotation part LP,and the rotation part LP may be coupled to the second surface SM-B ofthe support member SM through the rotation shaft CL. Thus, when therotation part LP moves about the rotation shaft CL, the first and secondconnection parts LK1 and LK2 may move together with the rotation shaftCL.

In an embodiment, the elastic part SP-A may be connected to the secondsurface SM-B of the support member SM and to the first connection partLK1, the rotation part LP or the second connection part LK2. In oneembodiment, for example, one end (e.g., a first send) PM0 of the elasticpart SP-A may be fixed to the second surface SM-B of the support memberSM overlapping the second display portion DA2, and another end (e.g., asecond end) PM1 of the elastic part SP-A may be connected to the firstconnection part LK1.

The elastic part SP-A or SP-B may be a member having restoring force. Inone embodiment, for example, the elastic part SP-A or SP-B may includeat least one of various members having elasticity, such as an elasticband and a spring. In an embodiment, where the elastic part SP-A or SP-Bis a spring having elasticity, the elastic part SP-A or SP-B may be acoil spring, a plate spring, a hydraulic spring, a tension spring, or atorsion spring, for example.

In an embodiment, the elastic part SP-A or SP-B may be the tensionspring. Thus, when the first connection part LK1 moves in a directionfrom the central portion CA toward the first folding portion FD1, thefirst connection part LK1 may be easily returned in a direction from thecentral portion CA toward the second folding portion FD2 by therestoring force of the elastic part SP-A provided as the tension spring.

The wire part WR may be connected to the second connection part LK2 andthe second surface SM-B of the support member SM. In one embodiment, forexample, one end (e.g., a first end) PM2 of the wire part WR may beconnected to the second connection part LK2, and another end (e.g., asecond end) PM3 of the wire part WR may be fixed to the second surfaceSM-B of the support member SM overlapping the first display portion DA1.

According to an embodiment of the invention, in the first state, thefirst connection part LK1 may overlap the second folding portion FD2.The first connection part LK1 may support the second hinge portion HG2in the first state, and thus the second folding portion FD2 may not befolded before the first folding portion FD1 is folded.

FIG. 5B illustrates arrangement of the components included in the guideunit LM in the second state of the display module DM (i.e., the state inwhich the display module DM is folded about the first folding axis FX1;see FIG. 3A).

According to an embodiment of the invention, the wire part WR may beconnected to the second connection part LK2 and the second surface SM-Bof the support member SM overlapping the first display portion DA1.Thus, when the first folding portion FD1 is folded about the firstfolding axis FX1 (see FIG. 3A), the second connection part LK2 may movein the direction from the central portion CA toward the first foldingportion FD1. In such an embodiment, the rotation part LP connected tothe second connection part LK2 may be rotated about the rotation shaftCL, and the first connection part LK1 may be moved by the rotation ofthe rotation part LP.

According to an embodiment of the invention, in the second state (seeFIG. 3A), the first connection part LK1 may be spaced apart from thesecond folding portion FD2. The first connection part LK1 may be spacedapart from the second hinge portion HG2 in the second state, and thusthe second folding portion FD2 may be in-folded or out-folded as desiredby a user.

When the first folding portion FD1 and the second folding portion FD2are unfolded by a user, the first connection part LK1 may be easilyreturned to a position overlapping the second hinge portion HG2 by therestoring force R of the elastic part SP-B.

The elastic part SP-A of FIG. 5A and the elastic part SP-B of FIG. 5Bare indicated by different reference characters for the purpose ofshowing different states of the display module DM. However, the elasticpart SP-A of FIG. 5A and the elastic part SP-B of FIG. 5B correspond toa same component.

According to an embodiment of the invention, the second folding portionFD2 having the radius of curvature equal to or greater than that of thefirst folding portion FD1 may be folded after the second state in whichthe first folding portion FD1 having the relatively small radius ofcurvature is folded. Thus, since the folding order of the foldingportions FD1 and FD2 is determined by the guide unit LM, interferencebetween folded areas may be minimized. As a result, damage of thedisplay device ED may be effectively prevented and reliability of thedisplay device ED may be improved.

According to an embodiment, the guide unit LM may further include wallparts GM1 and GM2. The wall parts GM1 and GM2 may be disposed on thesecond surface SM-B of the support member SM. The wall parts GM1 and GM2may guide movement directions of the first and second connection partsLK1 and LK2. Thus, even when the display device ED is repeated foldedand unfolded by a user, the first and second connection parts LK1 andLK2 may be moved to the same positions by the wall parts GM1 and GM2.

FIG. 6A is a plan view illustrating a display module according to analternative embodiment of the invention. FIG. 6B is a plan viewillustrating a state in which the display module of FIG. 6A is folded.FIG. 7A is a plan view illustrating a display module according toanother alternative embodiment of the invention. FIG. 7B is a plan viewillustrating a state in which the display module of FIG. 7A is folded.FIG. 8A is a plan view illustrating a display module according toanother alternative embodiment of the invention. FIG. 8B is a plan viewillustrating a state in which the display module of FIG. 8A is folded.Hereinafter, the same or like components in FIGS. 6A to 8B as thosedescribed above with reference to FIGS. 1 to 4B will be indicated by thesame reference characters, and any repetitive detailed descriptionthereof will be omitted.

Referring to FIGS. 6A and 6B, an embodiment of a display module DM1 mayinclude an elastic part SP1-A or SP1-B disposed on the second surfaceSM-B of the support member SM overlapping the central portion CA. Oneend (e.g., a first end) PM0 of the elastic part SP1-A or SP1-B may befixed to the second surface SM-B of the support member SM overlappingthe central portion CA, and another end (e.g., a second end) PM1 of theelastic part SP1-A or SP1-B may be connected to the rotation part LP.

In such an embodiment, the elastic part SP1-A or SP1-B may be acompression spring. The elastic part SP1-A or SP1-B may have compressivestress in a process changed from the first state into the second state.In a process of unfolding the first folding portion FD 1 and the secondfolding portion FD2 by a user, the first connection part LK1 may beeasily returned to a position overlapping the second hinge portion HG2by the restoring force R of the elastic part SP1-A or SP1-B.

The elastic part SP1-A of FIG. 6A and the elastic part SP1-B of FIG. 6Bare indicated by different reference characters for the purpose ofshowing different states of the display module DM1. However, the elasticpart SP1-A of FIG. 6A and the elastic part SP1-B of FIG. 6B correspondto the same component.

Referring to FIGS. 7A and 7B, an alternative embodiment of a displaymodule DM2 may include an elastic part SP2-A or SP2-B disposed on thesecond surface SM-B of the support member SM overlapping the centralportion CA. One end (e.g., a first end) PM0 of the elastic part SP2-A orSP2-B may be fixed to the second surface SM-B of the support member SMoverlapping the central portion CA, and another end (e.g., a second end)PM1 of the elastic part SP2-A or SP2-B may be connected to the rotationpart LP.

In such an embodiment, the elastic part SP2-A or SP2-B may be acompression spring. The elastic part SP2-A or SP2-B may have compressivestress in a process changed from the first state into the second state.In a process of unfolding the first folding portion FD1 and the secondfolding portion FD2 by a user, the first connection part LK1 may beeasily returned to a position overlapping the second hinge portion HG2by the restoring force R of the elastic part SP2-A or SP2-B.

The elastic part SP2-A of FIG. 7A and the elastic part SP2-B of FIG. 7Bare indicated by different reference characters for the purpose ofshowing different states of the display module DM2. However, the elasticpart SP2-A of FIG. 7A and the elastic part SP2-B of FIG. 7B correspondto the same component.

Referring to FIGS. 8A and 8B, another alternative embodiment of adisplay module DM3 may include an elastic part SP3-A or SP3-B disposedon the second surface SM-B of the support member SM overlapping thecentral portion CA. One end (e.g., a first end) PM2 of the elastic partSP3-A or SP3-B may be connected to the second connection part LK2, andanother end (e.g., a second end) PM3 of the elastic part SP3-A or SP3-Bmay be fixed to the second surface SM-B of the support member SMoverlapping the first display portion DA1.

In such an embodiment, the elastic part SP3-A or SP3-B may be a tensionspring. The elastic part SP3-A or SP3-B may have tensile stress in aprocess changed from the first state into the second state. In a processof unfolding the first folding portion FD1 and the second foldingportion FD2 by a user, the first connection part LK1 may be easilyreturned to a position overlapping the second hinge portion HG2 by therestoring force R of the elastic part SP3-A or SP3-B.

In such an embodiment, since the one end PM2 of the elastic part SP3-Aor SP3-B is connected to the second connection part LK2 and the otherend PM3 of the elastic part SP3-A or SP3-B is fixed to the secondsurface SM-B of the support member SM overlapping the first displayportion DA1, the wire part WR may be omitted.

The elastic part SP3-A of FIG. 8A and the elastic part SP3-B of FIG. 8Bare indicated by different reference characters for the purpose ofshowing different states of the display module DM3. However, the elasticpart SP3-A of FIG. 8A and the elastic part SP3-B of FIG. 8B correspondto substantially same component.

FIG. 9A is a plan view illustrating a display module according toanother alternative embodiment of the invention. FIG. 9B is a plan viewillustrating a state in which the display module of FIG. 9A is folded.Hereinafter, the same components in FIGS. 9A and 9B as those describedabove with reference to FIGS. 1 to 4B will be indicated by the samereference characters, and any repetitive detailed description thereofwill be omitted.

Referring to FIGS. 9A and 9B, in an alternative embodiment, a guide unitLM-A of a display module DM4 may include a rotation part LP, a firstconnection part LK1, a second connection part LK2, a wire part WR, anelastic part SP4-A or SP4-B, a first sub-connection part SL1, and asecond sub-connection part SL2.

The first sub-connection part SL1 may connect the first connection partLK1 and the rotation part LP. The first connection part LK1 and therotation part LP may be connected to one end (e.g., a first end) SC1 andanother end (e.g., a second end)

SC2 of the first sub-connection part SL1, respectively.

The second sub-connection part SL2 may connect the second connectionpart LK2 and the rotation part LP. The rotation part LP and the secondconnection part LK2 may be connected to one end (e.g., a first end) SC3and another end (e.g., a second end) SC4 of the second sub-connectionpart SL2, respectively. The sub-connection parts SL1 and SL2 may movefluidly in a change process between the first state and the secondstate.

The elastic part SP4-A of FIG. 9A and the elastic part SP4-B of FIG. 9Bare indicated by different reference characters for the purpose ofshowing different states of the display module DM4. However, the elasticpart SP4-A of FIG. 9A and the elastic part SP4-B of FIG. 9B correspondto the same component.

FIG. 10 is a plan view illustrating a display module according toanother alternative embodiment of the invention. Hereinafter, the samecomponents as described with reference to FIGS. 1 to 4B, 9A and 9B willbe indicated by the same reference designators, and the descriptionsthereto will be omitted.

Another alternative embodiment of a display module DM5 may include anelastic part SP-T disposed between the rotation part LP and the secondsurface of the support member SM overlapping the central portion CA.

In such an embodiment, the elastic part SP-T may be a torsion spring.The elastic part SP-T may have stress in a direction opposite to arotation direction of the elastic part SP-T in a process changed fromthe first state into the second state. In a process of unfolding thefirst folding portion FD1 and the second folding portion FD2 by a user,the first connection part LK1 may be easily returned to a positionoverlapping the second hinge portion HG2 by torque of the elastic partSP-T.

According to embodiments of the invention, the guide unit may bedisposed under the display module including a plurality of the foldingportions, and thus the folding order of the folding portions may bedetermined. In such embodiment, a folding operation of the foldingportion having a relatively small radius of curvature may be performedprior to a folding operation of the folding portion having a relativelygreat radius of curvature, and thus the interference between the foldingportions may be reduced to improve the reliability of the displaydevice.

While the invention have been described with reference to exampleembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from thespirits and scopes of the invention. Therefore, it should be understoodthat the above embodiments are not limiting, but illustrative. Thus, thescopes of the invention are to be determined by the broadest permissibleinterpretation of the following claims and their equivalents, and shallnot be restricted or limited by the foregoing description.

What is claimed is:
 1. A display device comprising: a display moduleincluding: a display panel including a front surface and a rear surfaceopposite to the front surface; and a support member including a firstsurface facing the rear surface of the display panel and a secondsurface opposite to the first surface; and a guide unit disposed on thesecond surface of the support member, wherein the display moduleincludes: a first folding portion foldable with a radius of curvature; asecond folding portion spaced apart from the first folding portion andfoldable with a radius of curvature, which is equal to or greater thanthe radius of curvature of the first folding portion; a central portiondisposed between the first and second folding portions; a first displayportion spaced apart from the central portion with the first foldingportion interposed therebetween; and a second display portion spacedapart from the central portion with the second folding portioninterposed therebetween, wherein the guide unit comprises: a rotationpart overlapping the central portion; a first connection part connectedto the rotation part; a second connection part spaced apart from thefirst connection part and connected to the rotation part; a wire partincluding a first end fixed to the first display portion and a secondend fixed to the second connection part; and an elastic part including afirst end fixed to the second surface of the support member and a secondend fixed to at least one part selected from the rotation part, thefirst connection part and the second connection part.
 2. The displaydevice of claim 1, wherein the first folding portion is foldable about afirst imaginary folding axis extending in a predetermined direction, thefirst connection part overlaps the second folding portion in a firststate in which the first folding portion is unfolded, and the firstconnection part is spaced apart from the second folding portion in asecond state in which the first folding portion is folded about thefirst imaginary folding axis.
 3. The display device of claim 2, whereinthe second folding portion is foldable about a second imaginary foldingaxis extending in the predetermined direction, and in the second state,the display module is in-folded in a way such that the second surface ofthe support member overlapping the first display portion overlaps thefront surface of the display panel overlapping the second displayportion.
 4. The display device of claim 2, wherein the second foldingportion is foldable about a second imaginary folding axis extending inthe predetermined direction, and in the second state, the display moduleis out-folded in a way such that the second surface of the supportmember overlapping the central portion overlaps the second surface ofthe support member overlapping the second display portion.
 5. Thedisplay device of claim 1, wherein the first end of the elastic part isfixed to the second surface of the support member overlapping the seconddisplay portion, and the second end of the elastic part is fixed to thefirst connection part.
 6. The display device of claim 1, wherein thefirst end of the elastic part is fixed to the second surface of thesupport member overlapping the central portion, and the second end ofthe elastic part is fixed to the rotation part.
 7. The display device ofclaim 1, wherein the first end of the elastic part is fixed to thesecond surface of the support member overlapping the first displayportion, and the second end of the elastic part is fixed to the secondconnection part.
 8. The display device of claim 1, further comprising: afirst sub-connection part connected to the first connection part and therotation part; and a second sub-connection part connected to the secondconnection part and the rotation part.
 9. The display device of claim 1,further comprising: wall parts which guide movement directions of thefirst and second connection parts.
 10. The display device of claim 1,wherein the elastic part includes a compression spring or a tensionspring.
 11. The display device of claim 1, wherein the elastic part isdisposed between the rotation part and the second surface of the supportmember overlapping the central portion, and wherein the elastic partincludes a torsion spring having a constant torque.
 12. The displaydevice of claim 1, wherein each of the first and second folding portionsincludes a hinge.
 13. A display device comprising: a display moduleincluding: a first folding portion foldable with a radius of curvatureabout a first imaginary folding axis extending in a predetermineddirection; a second folding portion foldable with a radius of curvature,which is equal to or greater than the radius of curvature of the firstfolding portion, about a second imaginary folding axis extending in thepredetermined direction; a central portion disposed between the firstand second folding portions; a first display portion spaced apart fromthe central portion with the first folding portion interposedtherebetween; and a second display portion spaced apart from the centralportion with the second folding portion interposed therebetween; and aguide unit disposed under the display module, wherein the guide unitincludes: a rotation part overlapping the central portion; a firstconnection part connected to the rotation part; and a second connectionpart spaced apart from the first connection part and connected to therotation part, wherein the first connection part overlaps the secondfolding portion in a first state in which the first folding portion isunfolded, and wherein the first connection part is spaced apart from thesecond folding portion in a second state in which the first foldingportion is folded about the first imaginary folding axis.
 14. Thedisplay device of claim 13, wherein the display module comprises: adisplay panel including a front surface and a rear surface opposite tothe front surface; and a support member including a first surface facingthe rear surface of the display panel and a second surface opposite tothe first surface.
 15. The display device of claim 14, wherein thesecond folding portion is folded about the second imaginary folding axisextending in the predetermined direction, and in the second state, thedisplay module is in-folded in such a way that the second surface of thesupport member overlapping the first display portion overlaps the frontsurface of the display panel overlapping the second display portion. 16.The display device of claim 14, wherein the second folding portion isfolded about the second imaginary folding axis extending in thepredetermined direction, and in the second state, the display module isout-folded in such a way that the second surface of the support memberoverlapping the central portion overlaps the second surface of thesupport member overlapping the second display portion.
 17. The displaydevice of claim 14, wherein the guide unit further comprises: a wirepart including a first end fixed to the first display portion and asecond end fixed to the second connection part; and an elastic partincluding a first end fixed to the second surface of the support memberand a second end fixed to at least one of the rotation part, the firstconnection part, or the second connection part.
 18. The display deviceof claim 17, wherein the first end of the elastic part is fixed to thesecond surface of the support member overlapping the second displayportion, and wherein the second end of the elastic part is fixed to thefirst connection part.
 19. The display device of claim 17, wherein thefirst end of the elastic part is fixed to the second surface of thesupport member overlapping the central portion, and wherein the secondend of the elastic part is fixed to the rotation part.
 20. The displaydevice of claim 17, wherein the first end of the elastic part is fixedto the second surface of the support member overlapping the firstdisplay portion, and wherein the second end of the elastic part is fixedto the second connection part.
 21. The display device of claim 13,further comprising: a first sub-connection part connected to the firstconnection part and the rotation part; and a second sub-connection partconnected to the second connection part and the rotation part.